Adjustable screw-lock pliers

ABSTRACT

A relatively stationary handle having a jaw structure normal to a longitudinally slotted structure that fits between the sides of a second slotted structure in a relatively movable handle having a second jaw structure parallel to said first jaw structure, said respective slots being adapted to normal intersection when said jaw structures are parallel. A cylindrical pivot block, diametrically tapped and passing transversely through the respective slotted structures, pivots the handles together and engages in said tap a threaded screw structure journaled in said first slotted structure of the relatively stationary handle, said screw structure extending through the handle end of said slot to engage a knurled thumb nut, the turning of which slidably opens said jaw structures, which are also pivotally openable around said pivot block by said relatively movable handles.

United States Patent [191 Burthardt 1 July 23, 1974 1 ADJUSTABLE SCREW-LOCK PLIERS [76] Inventor: Charles J. Burthardt, 1800 Elizabeth Ave., Metairie, La. 70003 22 Filed: May4, 1972 211 Appl. No.: 250,091

[52] U.S.Cl. ..81/401 [51] lnt. Cl B25!) 7/10 [58] Field of Search 81/389, 395, 398, 399, 8l/400,'401, 402, 403, 404, 405

I [56] References Cited 7 UNITED STATES PATENTS 244,269 7/1881 Lovrien 81/399 1,561,681 11/1925 Barnes 081/401 FOREIGN PATENTS OR APPLICATIONS 806,779 6/1951 Germany 81/404 Primary Examiner0thel1 M. Simpson Assistant Examiner-Roscoe V Parker N Attorney, Agent, or Firm-James B. Lake, Jr.

[5 7] ABSTRACT A relatively stationary handle having a jaw structure normal to a longitudinally slotted structure that fits} between the sides of a second slotted structure in a, relatively movable handle having a second jaw struc-l ture parallel to said first jaw structure, said respective; slots being adapted to normal intersection when said. jaw structures are parallel. A cylindrical pivot block,- diametrically tapped and passing transversely through the respective slotted structures, pivots the handles together and engages in said tap a threaded screw structure journaled in said first slotted structure of the relatively stationary handle, said screw structure extendingthrough the handle end of said slot to engage a knurled thumb nut, the turning of which slidably opens said jaw structures, which are also pivotally 1 C ai l m qs. P159135 oting and sliding the handle structures with respect to each other. I

The invention is a further improvement over my prior invention Improvement in Adjustable Pliers, Ser. No. 878,030, filed Nov. 19, 1969 and abandoned with the filing of a continuation-in-part Oct. 21, 1971, Ser. No. 191,309, entitled Adjustable Pivot Pliers now U.S. Pat. No. 3,768,346. I

It is old in the art to provide pliers that are adjustable both pivotally and slidably. I-Ieretofore the twohandle structures comprising a pair of pliers have been pinned together thereby offsetting the jaws by the thickness'of the pinned parts, and requiring that one or both of the jaws be oppositely deformed in order for full opposition of the jaws could be obtained. Additionally, the side by side pinning or pivoting subjects the handle structures to transverse and longitudinal and lateral strains affecting the strength, wear and rigidity of the pivoting of the pliers. j

An object of the invention is to-provide adjustable pliers in which one handle structure is pivoted within FIG. 7 is an elevational view of the rotatable acme threaded screw structure;

FIG. 8 is a side and end view of the cylindrical pivot block; and

FIG. 9 is a side and end view of the knurled thumb nut and a side view of the holding pin.

The following is a discussion and description of preferr'ed specific embodiments of the new adjustable screw-lock plier structures of this invention, such being made with reference to the drawings, whereupon the same reference numerals are used to indicate the same or similar parts and/or structure. It is to be understood that such discussion and description is not to unduly the other handle structure to provide a double'and more stable supports for the pivoting member.

Another object of the invention is to provide adjustable pliers in which full opposition of the jaws is obtained without offsetting one or both of saidjaws.

Still another object of this invention is to provide an adjustable plier, the jaw opening of which can be varied to any point between closed and full open, and which locks and will not slip at any point without any additional locking device.

' Another object of this invention is to provide an adjustable plier that can be operated and adjusted with one hand.

One other object of this invention is to provide an adjustable plier in which the grip or handle spread of the handles is the same when adjusted to fit any size object within the size range of the plier.

Another object of this invention is to provide an adjustable plierqin which the wearing or contact points will not show enough wear so as to be detrimental in the continued use of the plier. t

One further object of this invention is to provide an adjustable plier that is simple to use, economical to manufacture, and reliable in operation.

Various other objects, advantages and features of the invention will become apparent to those skilled in the art from the following discussion, taken in conjunction with the accompanying drawings, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a one-half scale side view of the assembled adjustable screw-lock plier;

FIG. 2 is a top view of the stationary handle structure taken along line 2-2 in FIG. 1;

FIG. 3 is a sectional view of the movable pivoting handle structure taken along line 3-3 in FIG. 1;

FIG. 4 is a sectional view of the full plier assembly taken along line 3-3 in FIG. 1;

FIG. 5 is a sectional view of the stationary handle structure taken along line 5-5 in FIG. 1;

FIG. 6 is a sectional view of the assembled plier structure taken along line 6-6 in FIG. 1;

limit the scope of the invention.

Referring to the drawings in detail and in particular to FIG. 1, the fully assembled adjustable screw-lock plier structure is indicated generally. More specifically the size and shape 'of the stationary slotted handle structure is shown with the curved handle 20 laterally expanding at 21 to form the enlarged slotted section 30-32, the thickness of which is the same as the handle 20. The slotted section 30-32 of the stationary handle structure is angled off laterally from the handle 20 at approximately to give access to the outside portion of the bottom slot 34 which contains the bottom axially centered retaining bearing hole for the lower shaft section 68 of the rotatable acme threaded screw 60. The shape of the round-ended, elongated, parallel sided, open slot'36 is shown which contains the top axially centered bearing hole 28 thru the top section of this slotted portion of the stationary handle structure. The top portion of the slot structure of the stationary handle structure enlarges and thickens at 26 to form a heavier cross-section to reinforce the structure around the bearing hole 28 and the toothed 24 jaw structure 22 extends laterally at 90 from the longitudinal axis of the slot section to form the upper jaw of the plier. Again in FIG. 1, the rotatable acme threaded screw structure is shown assembled and axially centered and retained within the slot of the stationary handle-jaw structure by the top bearing 28 and the lower bearing 34 with the adjusting knurled thumb nut 80 fastened externally to its lower shaft 68 by the holding pin 88 while the screw portion of the rotatable acme threaded screw structure 60 passes thru and engages the internal acme threads I of the cylindrical pivot block 70. The cylindrical pivot block 70'while mounted on the screw 60 of the rotatable screw structure thru its diametrically centered internally acme threaded hole that is centered on its longitudinal axis is also diametrically fitted to and rides on the internal sides of the'slot 36 in the stationary handle structure. The exterior ends of the cylindrical pivot block 70 protrude past the slot 36 on both sides of the stationary handle-jaw structure and thru the bearing holes 54 of the side members 44 of the movable pivoting handle structure 40 in such a manner as to form a bearing 54 and'pivot point for the movable pivoting handle structure 40that is transportable or movable up and down the slot of the stationary handle structure which furnishes the means of varying the jaw opening of the plier while at the same time allowing the movable handle to pivot for gripping an object. FIG. 1 shows the movable pivoting handle structure with the handle structure 40 and the toothed 52 jaw structure 46 attached together by means of the side plates 48 which are firmly fastened and made a part of the movable pivoting handle structure by means of the braded pins 58 which pass thru the jaw 46 and each side plate 48 and in turn thru the handle 40 and each side plate 48 in such a manner as to form the lateral slot the width of which is the thickness of the slotted section of the stationary handle structure and whose length extends from the upper portion 42 of the handle 40 to the inner portion 50 of the jaw 46. Each side plate 48 is centrally drilled to form a hole 54 to accommodate the cylindrical ends of the cylindrical pivot block 70 and thus form a pivot bearing, 54 for the movable pivoting handle structure.

The top view of the structure in FIG. 2 illustrates the top of the extended toothed jaw 22 of the stationary handle structure and the expanded section 26 around the drilled hole 28 which is centered over the top of the slot and which forms a top bearing 28 for the top 62of the rotatable acme threaded screw 60 shown in FIG. 1. The screwdriver slot 64 in the top of the rotatable acme threaded screw 60 is shown at 64 in'FIG. 2 and is for the purpose of assembly of the plier structure.

The cross-sectional view of the movable pivoting handle structure shown in FIG. 3'taken along line 3-3 in FIG. 1 illustrates the jaw 46, the handle 40, and the side plates 48 and 45 with the drilled pivot bearing holes 54 and 56 which are firmly and permanently held together by the braded pins 58 in such a manner as to form the slot 43 between the side plates 48 and 45 and the inner part 50 of the jaw section 46 and thetop 42 of the handle 40.

The cross-sectional view of the full plier assembly in FIG. 4 is taken at the same line 33 on FIG. l'as that of FIG. 3 and illustrates the cylindrical pivot block 70 engaged on the threads 72 of the rotatable acme threaded screw 60 with its external cylindrical ends 70 forming the pivoting bearing surface 54 for the bearing holes 54 in the side plates 48 and 45 of the movable pivoting handle structure shown in FIG. 3. The front 31 and rear 30 sectionsof the slotted section of the stationary handle structure indicatethe width of this slot and the slight clearance 33 allowed for the travel of the cylindrical pivot block 70 within the slot when the screw 60 is rotated to move the block 70 up and down the slot in the stationary handle structure. It is seen that the thickness of the front 31 and rear 30 sections of the slotted section of the stationary handle structure is the same as the width of the slot 43 in the movable pivoting handle structure shown in FIG. 3 in order to furnish additional bearing surface between the two handle surfaces which in turn holds the respective plier jaws and plier handles in close alignment. The openings 57 and 55 between the slot sections 31 and30 of the stationary handle structure shown in FIG. 4 and the slot ends 50 and 42 shown in FIG. 3 of the movable pivoting handle structure allow clearance for pivoting the movable pivoting handle structure about the cylindrical pivot block 70 while contained on the stationary handle structure in order to exercise the gripping action of the plier.

The cross-sectional view taken along -5 in FIG. 1 and shown in FIG. 5 illustrates the bottom of the slot section 34 of the stationary handle structure with the bearing hole 35 that is axially centered thru the bottom of the slot 34 shown in FIG. land provides a retaining bearing for the shaft 68 on the lower end of the rotatable screw structure 60.

The cross-sectional view of the full plier assembly in FIG. 6 is taken along line 6-6 in FIG. 1 and illustrates a vertical view of the slot section of the stationary handle structure with the top portion 62 of therotatable screw structure 60 in place within the centered bearing hole 28 in the expanded top section 26 of the slot section of the stationary handle structure and the shaft portion 68 of the rotatable screw structure 60 in place within the centered bearing hole 35 in the bottom section 34 of the slot section of the stationary handle structure. The diameter of the shaft 68 of the rotatable screw structure 60 being smaller than the screw diameter at the bottom of the thread creates a shoulder at 66 on the rotatable screw structure which bears at this point on the bottom of the slot in the slot section of the stationary handle structure. The knurled thumb nut 80, center drilled to fit the shaft 68 of the rotatable screw structure 60, is mounted and fastened thereon by handle structure between the shoulder 66 on the screw .tion is intended to illustrate and not structure and the top of the knurled thumb nut 80. The internally threaded 72 cylindrical pivot block is mounted on and engaged with the acme thread on the rotatable screw structure 60 with the extended cylindrical ends 70 passing thru the pivot bearing holes in the side members 45 of the slot section'of the movable pivoting handle-jaw structure.

A full view of the rotatable screw structure 60 is shown in FIG. 7 which illustrates the screwdriver slot 64 in the top bearing section 62, the fast action acme threaded shaft wherein the thread pitch is approximately one-half the thread diameter, the shoulder 66, and the lower reduced size shaft 68 with the drilled hole 76 for the holding pin.

A side and end view of the cylindrical pivot block 70 are shown in FIG. 8 with the internal acme threaded hole indicated at 72.

A side and an end view of the knurled 86 thumb nut 80 areshown in FIG. 9 which illustrate the longitudinal drilled hole 82 to fit the lower shaft of the rotatable screw structure and the diametrically drilled hole 84 to accommodate the pin 88 which fastens the knurled thumb nut 80 on the lower shaft of the rotatable screw structure.

It is seen that the adjustable screw-lock plier structures of this invention provide new and simplified means of adjusting the size of the jaw opening andis locked in place at any point desired by the pivot block on the rotatable screw structure while furnishing a pivotable fastening for the movable handle. The adjustable screw-lock plier structure is easy to use and adjust with one hand, and therefore, provides useful advantages over currentadjustable pliers.

While the invention has been described in connection with preferred specific embodiments thereof, it will be understood that this specification and descripto limit the scope of the invention. I

What is claimed is:

1. In a pair of adjustable screw-lock pliers having angled jaws with slots defined in plier sides adjacent said angled jaws for interfitting said slotted plier sides transversely, and having a threaded screw, with unthreaded said threaded screw intermediate its supported ends; and means for manually rotating said threaded screw relative to said combination pin and bearing block for moving it longitudinally in said one of said slots and thereby space apart said angled jaws with tangentially minimum friction between moving parts and maximum bearing support for said threaded screw. 

1. In a pair of adjustable screw-lock pliers having angled jaws with slots defined in plier sides adjacent said angled jaws for interfitting said slotted plier sides transversely, and having a threaded screw, with unthreaded ends, rotatably supported by said ends longitudinally in one of said slots and transverse the other: a combination cylindrical pivot pin, plier connecting pin and bearing diametrically tapped to threadably engage said screw, and sized longitudinally and radially to pivot in holes transversely defined in the sides of the other of said slots and engage tangentially and slidably the sides of said one of said slots for pivotally connecting said interfitting plier sides and to provide a third support for said threaded screw intermediate its supported ends; and means for manually rotating said threaded screw relative to said combination pin and bearing block for moving it longitudinally in said one of said slots and thereby space apart said angled jaws with tangentially minimum friction between moving parts and maximum bearing support for said threaded screw. 